Hygrometer and other instrument.



E H. BRISTOL & W. H. FITTS.

HYGROMETER AND OTHER INSTRUMENT.

APPLICATION FILED JAN. 18. tars.

1,243,671 Patented Oct. 16,1917.

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UNITED STATES PATENT OFFICE.-

EDGAR H. BRISTOL AND WALTER HENRY FITTS, 0F FOXBORO, MASSACHUSETTS,

ASSIGNORS TO THE INDUSTRIAL INSTRUMENT COMPANY, OF FOXBORO, MASSA- CHUSETTS, A CORPORATION OF CONNECTICUT.

HYGROMETER AND OTHER INSTRUMENT.

Application filed January 18, 1913. Serial 170. 742,777. r

T 0 all whom it may concern:

Be it known that we, EDGAR H. BRISTOL and WALTER H. Frr'rs, citizens of the United States, and residents of Foxboro, in the county of Norfolk and Commonwealth of Massachusetts, have invented an Improvebest understood by reference to the following description of an illustrative embodiment thereof shown in the accompanying drawing, wherein: A

Figure 1 is a front elevation of an illustrative hygrometer embodying the invention; I

Fig. 2 is a side elevation of Fig. 1;

Fig. 3, on an enlarged scale, is a sectional detail of parts of the mechanism; and

Fig. 4 is a section taken on line 44 of Fig. 3.

Referring to the drawing, the illustrative instrument therein shown as embodying the invention comprises a casing 1 of any usual construction, within which there is mounted a chart 3 graduated radially to represent periods of time and circularly to represent a scale of temperature. This chart may be detachably secured to a spindle 5 driven by any suitable means, such for example as the time train of a clock mechanism.

A pair of indexes or pointers, in the illustrative embodiment, pen indexes 7 and 9, mounted and driven as hereinafter described, may be arranged totravel in a generally radial direction over the chart 3 in order to indicate or record thereon temperatures prevailing at or during any instant, or period of time.

For the purposes of the specific instrument, there are mounted, at the rear of the casing, temperature-responsive elements exemplified herein as helically coiled tubes 11 and 13 of flattened cross sectional shape. These tubes are filled with alcohol or other suitable liquid and then sealed. These tubes Specification of Letters Patent.

Patented Oct. 16, 1917.

preferably are arranged in tandem and have ends 11 and 13, respectively fixed by straps 11 and 13 to an elongated bracket pipe 15 paralleling said tubes, said straps'being conveniently soldered to said helical tubes and to said bracket pipe. To secure the latter to the rear of the casing it may have an end threaded in a union 17, conveniently integral with a plate 19 held to the rear face of said casing by suitable screws 21. I

The variations of temperature will cause the liquid in the tubes 11 and 13 to expand or contract and thereby produce in the tubes a rotary tendency about their axes, and the free ends of said tubes will thereby have a substantial circumferential movement.

To transmit the movement of the free end of the tube 13 to the index 7 the latter is secured to a shaft 23, having a reduced end 25 journaled in a bearing plate 27 mounted on posts 29 projecting through an aperture in the back plate of the casing to find support in the plate 19 referred to. The opposite end of said shaft 23 is connected to the movable portion of the helically coiled tube 13 by a suitable radially extensible, but preferably circumferentially rigid, driving connection, herein comprising a fiat, ribbonlike arm 31 fixed at one end to the tube 13, and at its opposite end to the shaft 23 in any suitable manner, as by soldering, said arm extending from said tube obliquely to said shaft. By this construction the arm transmits without loss of motion the rotative movement of the tube to the shaft, and at the same time permits the coils of the tube tcl 1 expand and contract more or less radia y.

To transmit movement of the free end of the tube 11 to the index 9, the latter is provided with a boss 31 loose on the reduced end 25 of the shaft 23 and secured to one end of a U-shaped bar 33, paralleling the shaft 23 and having its ends apertured to receive said shaft. The bar 33 is connected to the movable end of the expansion tube 11 by a fiat ribbon-like arm 35, somewhat similar to the arm 31 described for transmitting movement from the expansion tube 13 to the shaft 23.

The index boss 31 and the reduced end of the shaft 25 are so arranged that the boss and shaft may have more or less relative mdexes.

Theftubes and the ribbon-like arms for Ytransmitting movement from the tubes to the shaft are in some respects similar to that shown and claimed in the copending ap lication of Edgar H. Bristol Serial 0. 673,525 filed January 26, 1912.

To provide data for ascertaining the hygrometric conditions of the atmosphere the tube llis dry and responsive to natural changes in the temperature of the atmosphere surrounding the same, but the tube 13 should be maintained moist. To this end it is enveloped in a casing or wick 37 of silk or other suitable materialhaving a portion 39 immersed in water, or other suitable liquid, for conducting the proper amount of moisture to the'envelop proper and to the tube 13.

To feed liquid to the fabric envelop 37 the bracket pipe 15, referred to, is utilized and is provided with a longitudinally extending slot 43 through which the envelop portion 39 may be entered and be immersed in the liquid contained in said pipe. An important feature of the invention relates .to means for supplying and controlling thefeeding of the liquid to said envelop. To this end there is provided a reservoir conveniently in the form of a bottle 45 removably supported between resilient arms 4:7 projecting rearwardly from the casing 1. The neck of the bottle may be introduced to and seated in a'receiver or cup 49 mmmunicating through a pipe 51 and the union with the envelop receiving pipe-15. To contribute to the support of sand receiver it maybe connected to the rear face of thecasing 1 by a. bracket 53.

The bottle 45 being closed, with the ex ception of the opening afforded by its neck, renders it necessary to remove the same from said receiver 49 to permit the filling thereof. To prevent escape of the water from the bottle when it is inverted for presentation to the receiver cup, suitable valve means is provided, herein typified as a conical valve 55 of rubber, or other suitable material,

adapted to seat itself on the opening formed at the juncture of the neck with the body of the bottle. It will be apparent that, when the bottle is inverted with water in it, the pressure of the water will force the valve 55 toward and maintain the same on its seat.

When the bottle is introduced to the receiver 49 it is desirable to automatically open the valve to permit the feeding of the water from the bottle into the receiver. To this endthe valve 55 is connected by a rod 5 with an operating member conveniently in the form of a short tube 59 extending transversely across the end of the neck of the bottle. By this construction, when said neck is introduced into the receiver the short tube 59 will rest a ainst the bottom of the cup, and the rod 57, eing longer than the neck of the bottle, when the neck of the bottle is moved down into contact with said short tube, will lift the valve 55 from its seat. The latter may conveniently constitute a rest for supporting the neck of the bottle a desired distance from the bottom of the cup to permit the flow of liquid from the bottle into said receiver. 1

When the bottle is positioned with its neck in the receiver, as described, the end of the neck will-be sufiiciently spaced from the bot- ,tom of the receiver to permit a supply of water to flow from the bottle into the receiver, thence into the ipe 51 and the tube 15. The water will ow from the bottle until it rises in the cup to the end ofthe bottle neck. On the occurrence of this event, the neck of the bottle is sealed and the flow from the bottle is arrested.

Preferably the neck of the bottle should bein such a position as to maintain the water at such a level as merely partially to fill the tube 1.5, in order that there may be no possibility of forcing the liquid too rapidly to the tube containing envelop or creating leakage through the tube slot 43.

After a time-the charge of liquid in the tube 15 will be absorbed by the envelop sufliciently. to cause the liquid level in the receiver 49 to drop beneath the end of the bottle neck. This will permit-the ingress of air to said neck, and cause the feed of :1

fresh supply of water from the bottle sufiicient-to raise again the level of the water in the cup to the end of the neck, whereupon the neck is closed and the feed from the bottle is arrested.

By the above described 'construction the I feed of the water from the bottle to the absorbent envelop is automatically controlled or regulated so that a desired and prolonged su ly of water is had to the envelop.

0 protect the expansion tubes and the with legs 65 extending rearwardly from said casing, and having feet 67 for receiving suitable screws for securing said legs to a wall or other placedesired.

The tube 11 is responsive to the natural tem erature of the atmosphere and the liquid therein expands or contracts according to temperature changes. These changes are indicated and recorded on the chart 3 by the index. 9. The evaporation of the moisture from the envelop containing the tube 13 will cause the temperature, of said tube to be less than that of thetube 11. As a result, the tube 13 will expand less than the tube 11. The index 7 will indicate and record this reduced temperature on the chart 3. These temperatures, and the differences between them, afford the data for determining the hygrometric conditions of the atmosphere, which may be ascertained by reference to empirical tables.

The dry and wet expansion tubes, constructed and arranged as described, and the connections therefrom to the indexes, provide a simple and effective mechanism for indicating and recording the temperature changes.

The reservoir is sufficiently large to contain a large supply of water, the feed of which is regulated and controlled so that the water is fed to the absorbent envelop as required.

While the water feed regulating device is described herein in connection with the supplying of water to the wet tube of a hygrometer, it will be understood that its field of use is not limited thereto, but that it may 'be applied for other purposes as desired. Also the mechanism for transmitting movements from the responsive members to the indexes may be applied to other instruments.

It is to be understood that the invention is not limited to the specific construction, organization and mode of operation. above described; on the contrary, the invention may be variously embodied and the described features may be used in various combinations and sub-combinations.

What we claim as new and desire to secure by Letters Patent is:

- 1. An instrument of the class described comprising, in combination, indexes; helical tube responsive members arranged in tandem and having fixed and movable ends, shaft means for connecting said movable ends to said indexes respectively; absorbent material for one of said members; means to conduct moisture to said material; and a reservoir separate from said conducting means for supplying moisture thereto.

2. An instrument of the class described comprising, in combination, indicating means, helical tube. responsive members for governing said indicating means, absorbent material for one of said members; a slotted container receiving a portion of said material; a reservoir having an outlet for communication with said container and valve means for said outlet having provision for automatically opening the latter on presentation of said reservoir to said container.

3. An instrument of the class described comprising, in combination, indicating means; helical tube responsivemembers for governing said indicating means; a slotted container; absorbent material for one of said members having a portion entered through and closing the slot in said container; and a closed reservoir having a sin gle opening and separable from said container,jsaid reservoir having provision for automatically supplying moisture to said container as rapldly as it is consumed by said material.

4. An instrument of the class described comprising, in combination, indicating means; responsive members; means to transmit movement from said responsive members to said indicating means; a container; absorbent material for one of said members and having a portion entered into said container; and a reservoir for separable association with said container and having provision for automatically supplying moisture to said container proportionately to the consumption thereof by said material.

5. An instrument of the class described comprising, in combination, indicating means; responsive members for governing the same; a container; absorbent material for one ofsaid members; a reservoir for supplying moisture to said container and material; and shaft means for transmitting movement from said responsive members to said indicating means and partially supported by said members.

6. An instrument of the class described comprising, in combination, indexes; helical tube responsive members for governing said indexes respectively; a fixed bearing; shaft means journaled therein {means connecting said members to said shaftmeans and having provision for contributing'to the sup port of the latter; and'means connecting said shaft means with said indexes respectively.

7. An instrument of the class described comprising, in combination, indexes; helical tube responsive members arranged in tandem for governing said indexes respectively; a container; absorbent material for one'ol said members having a portion in serted in said container; a housing for said members and container; and a reservoir for supplying moisture to the latter.

8. A hygrometer comprising in combination, indexes, temperature responsive members, means for transmitting movement from said members to said indexes respectively; a conta1ner,'a w ck extending from said contamer to one of sa1d members and a reservoir detachably associated with said container for supplying water thereto.

9. A hygrometer comprising in combination, a casin a dial plate therein, index means movab e relatively to said plate, wet

and dry temperature responsive members, means for transmitting movements from said members to said index means; a wick for said wet member, a container receiving said wick, a reservoir for supplying water to said container and means for automatically maintaining a predetermined level of water in said container.

10. A by rometer comprising in combi- 15 nation, a dial, indexes movable over said It is hereby certified that Letters Patent No. 1,243,671, granted October 16, v 1917, upon theapplication of Edgar H. Bristol and Walter Henry Fitts, of Foxboro, Massachusetts, for an improvement Hygrometers and Other Instruments," were erroneously issued to The Industrial Instrument Company, of Foxboro,

have been issued to The Foaboro Lbmpa ny, of 'Foxboro, Massachusetts, a corporation of Massachusetts, saidhorporation being owner, by mesne assignments, of the entire interest in said invention as shown by the records of assignments in this oflice; and that the said Letters Patent should be readwith this correction therein that the same may conform to the record of the casein the Patent Ofiice. I

4 Signed and sealed this 20th day of November A. D., 1917.

' R. F. WHITEHEAD,

[snALJ Acting Uommissioner of Patents.

Corre'ction'in Letters Patent No. 1,243,671.

Massachusetts, a corporation of Connecticut, whereas said Letters Patent should 

